- Bublitz, Walter J.
Forest Research Laboratory, School of Forestry, Oregon State University
A study has been made of the kraft pulping characteristics of thinnings from young Douglas-fir trees. The yields and permanganate numbers of the thinnings pulps were within commercially acceptable limits. The strength properties of the thinnings pulps were somewhat influenced by the relatively high percentage of juvenile wood, but as a whole they were comparable to those of commercial Douglas-fir kraft pulp from more mature trees. The presence of bark in the chips generally reduces the pulp yield and strength, but the loss of economic value in yield and quality must be related to the cost of debarking these small trees in order to evaluate properly the role of thinnings in the raw material picture of pulpwood.